Source: http://www.abarim-publications.com/Meaning/Zalaph.html

🔼The name Zalaph in the Bible

The name Zalaph occurs only once in the Bible. He was the father of Hanun, who partook in the restoration work on the wall of Jerusalem after the return from the exile in Babylon (Nehemiah 3:30).

🔼Etymology of the name Zalaph

It's not wholly clear where the name Zalaph comes from or what it was supposed to mean, and it may even be a truncated form of the name Zelophehad (צלפחד).

One possibility is that our name derives from an Aramaic verb צלף (salap), meaning to break or rupture. This verb is not otherwise used in the Bible.

Another possibility is that it derives from the identical Hebrew word צלף (salap), which denotes the caper-plant. There is evidence that this word existed in post-Biblical times but none that it was in use during. In fact, in Ecclesiastes 12:5 the word אביונהabiyona occurs, which some translations (NAS, JSP, Darby) translate with caperberry.

🔼Zalaph meaning

For a meaning of the name Zalaph, NOBSE Study Bible Name List goes with the post-Biblical word and reads Caper-Plant. Alfred Jones (Dictionary of Old Testament Proper Names) sticks with the Aramaic and proposes Fracture.
BDB Theological Dictionary does not offer a perspective on this name.